Roads/Highways

A Behavioral Theory of Multi-Lane Traffic Flow Part I: Long Homogeneous Freeway Sections

Daganzo, Carlos F.
1999

This paper proposes a macroscopic behavioral theory of traffic dynamics for homogeneous, multi-lane freeways. The theory makes predictions for separate groups of lanes while recognizing that the traffic stream is usually composed of aggressive and timid drivers. Its principles are so simple that non-scientist drivers can understand them. The simplest version of the theory, which is described in its full complexity without calculus, is shown to be qualitatively consistent with experimental observations, including the most puzzling. Its predictions agree with the following phenomena: (i) the...

The Full Cost Of Intercity Transportation - A Comparison Of High Speed Rail, Air And Highway Transportation In California

Levinson, David
Gillen, David
Kanafani, Adib
Mathieu, Jean-michel
1996

The Full Cost of Intercity Transportation Page ES-1 This study evaluates the full cost of three modes of intercity transportation: air, highway, and high speed rail. The evaluation is done within the context of the California Corridor, connecting the Los Angeles Basin and the San Francisco Bay Area. The purpose of evaluating full cost is to compare the economic implications of investment in, or expansion of, any of these three modes. The scope of the analysis is full transportation cost. Full transportation costs includes external, or social cost, in addition to the internal costs of...

Empirical Study of Ramp Metering and Capacity

Cassidy, Michael J.
Rudjanakanoknad, Jittichai
2002

Traffic data near the junction of a single-lane on-ramp (with a ramp meter) and a three-lane freeway were measured for six weekdays during the rush and studied. On each of these days, the merge became a bottleneck with queue discharge rates that were substantially lower than the flows that had passed the merge prior to the bottleneck's activation. On some days, these earlier high flows persisted for many minutes. The bottleneck always occurred when inflows from the on-ramp surged in the presence of high flows arriving from the freeway. Often, the on-ramp surges persisted for no longer than...

Measuring the influence of recurring sporting events on freeway characteristics

Seeherman, Joshua
Anderson, Paul
2017

Freeway traffic is subject to the effects of recurring and non-recurring events. Changes in the traffic stream as a result of recurring special events, specifically sports, is an area that is not well researched. This study examined freeway detectors adjacent to two baseball stadiums in California to analyze the contribution of a baseball game to freeway flow and occupancy for weekday evening games. In addition, hourly volumes on local rail transit were analyzed in the San Francisco case. Findings include a statistically significant effect of baseball increasing the flow by approximately 1...

Spatiotemporal Studies of Traffic Phenomenon on Freeways with Limited-access Special Lanes

Cassidy, Michael J.
Kim, Kwangho
2015

Most special-use freeway lanes in the US, whether reserved for carpools, toll-paying commuters or both, are physically separated from the adjacent regular-use lanes by some form of barrier. Vehicle movements in and out of a special lane of this type are permitted only at select access points along the route. The barrier at each select point might open for a distance of 400 m or so. Limiting access in this way is said to reduce the “turbulence” that might otherwise occur were the special lane not to have a buffer, such that vehicles could instead enter or exit that lane anywhere along its...

A Behavioral Theory of Multi-Lane Traffic Flow Part II: Merges and the Onset of Congestion

Daganzo, Carlos F.
1999

This paper examines the behavior of multi-lane freeway traffic past on-ramps, building on the continuum model of part I and focusing on the onset of congestion. The main complication with merges is that rabbits (fast vehicles) entering from an on-ramp usually stay on the shoulder lane(s) of the freeway for some distance before merging into the fast lane(s). An idealization is proposed where this distance is taken to be the same for all vehicles. As a result, the system behaves as if there was a fixed buffer zone where entering rabbits cannot change lanes. The model of part I is extended to...

Causes And Effects Of Phase Transitions In Highway Traffic

Daganzo, C. F.
Cassidy, M. J.
Bertini, R. L.
1997

It is shown that all the phase transitions in and out of freely flowing traffic reported earlier for a German site could be caused by bottlenecks, as are all the transitions observed at two other sites examined here. Furthermore, all the evidence indicates that bottlenecks cause these transitions in a predictable way, and no evidence is found that stoppages (jams) appear spontaneously in free flow traffic for no apparent reason. The most salient phenomena observed at all locations are explained in terms of a simple theory specific to traffic.

California’s Freeway Service Patrol Program: Management Information System Annual Report Fiscal Year 2020-21

Mauch, Michael
Skabardonis, Alex
2022

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles and was later expanded to other regions by state legislation in 1991. As of June 2020, there were sixteen participating FSP Programs operating in California, deploying 305 tow trucks and covering over 1,900 (centerline) miles of congested California freeways. The...

California’s Freeway Service Patrol Program: Management Information System Annual Report Fiscal Year 2016-17

Mauch, Michael, PhD
Skabardonis, Alex, PhD
2018

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles, and was later expanded to other regions by state legislation in 1991. As of June 2017, there were fourteen participating FSP Programs operating in California, deploying 324 tow trucks and covering over 1,718 (center-line) miles of congested California freeways. The...

Critique of a Freeway On-Ramp Metering Scheme and Broader Related Issues

Cassidy, Michael J.
2002

Offered here is a critique of a simple scheme recently proposed for metering freeway on-ramps. An earlier report of this scheme's potential for reducing commuter delay is shown to be exaggerated. The discussion makes clear that to reduce delay, metering should increase the rates at which commuters exit the freeway. The scheme critiqued here, as well as other well-known metering algorithms, are shown to have deficiencies in this, particularly when the freeway is plagued by a diverge bottleneck with a congested off-ramp. Other more effective schemes for reducing the delay caused by these...